Where Sewage Might Be the Last Best Weapon To Help Predict COVID-19 Outbreaks

Columbia University engineering professor Kartik Chandran projected the current COVID-19 infection trends in New Jersey's most populous region almost a month before they happened.

“It's amazing because it allows us to make real advances in human health," Chandran said.

With the rise of the stealth omicron (BA.2) mutation, his work has become even more crucial. With fewer tests and more use of at-home quick kits, experts say the state's infection totals are drastically undercounted, even though the number of infections is going up.

The Institute for Health Metrics and Evaluation said last week that only 7% of coronavirus cases are found. That means that the real rate of cases is 14.5 times higher than what reports say.

Water monitoring may be the only way New Jersey can get an early warning.

While COVID-19 is a respiratory virus, health experts believe between 40% and 80% of infected persons shed the coronavirus in their feces. So atershed treatment plants like the one Chandran has been studying have become a key tool in assessing the pandemic.

Chandran has been taking samples of wastewater from sewer-shed facilities in Little Ferry and Edgewater since the first coronavirus outbreak happened in May 2020. This type of surveillance can show changes in COVID cases in an area for up to two weeks ahead of time, says Bergen County Executive Jim Tedesco.

After nearly two years, Chandran is delighted with the study's findings. His team was able to estimate the present spike of COVID-19 cases across the state.

Chandran says there was an increase in watershed sampling data in winter 2022, and it matched a rise in the amount of omicron cases. Though it dipped in early March, it has been steadily been increasing since.

On April 24, 2022, 1,527 fresh confirmed positive tests were reported in New Jersey. Over the weekend, there were 462 new hospitalizations. There were also 1,752 new confirmed cases across the state, which is up 123% from a month ago.

As such, the CDC recently changed the status of the spread of disease in Bergen and Morris counties to "medium." While the use of at-home test kits has slowed the spread of COVID-19, many health experts say it has made it harder to get accurate case counts.

Also, the CDC is cutting back on the number of labs it uses to look for new variants and is more and more looking at hospital admissions instead of positive tests as the most important pandemic data point.

For now, Dr. Amy Kirby, director of the CDC's National Wastewater Surveillance System, advises state health officials to use sewage data as a "early warning system." The CDC runs the National Wastewater Surveillance System and posts the data on its COVID-19 tracker.

While the Columbia researchers study the samples taken at the Bergen County sewer-shed facilities, the Passaic Valley Sewerage Commission agreed to join the National Wastewater Surveillance System in March.

Passaic County Executive Director Gregory Tramontozzi said that "feces is shed right away after a coronavirus infection." By joining the CDC's NWSS program, Tramontozzi says the state will be able to "grow our monitoring capability and continue to alert our communities."

Columbia's study comprises two sewer sheds that collect wastewater from 47 Bergen County townships, totaling 580,000 people. In total, the Passaic Valley treatment center serves more than 1.5 million people across five New Jersey counties.

Chandran admits wastewater surveillance only covers a portion of New Jersey, b ut he believes more sewer-shed plants will join in and help to identify and predict COVID-19 trends.

“The state reports COVID based on instances, which is never a clear snapshot because no one gets tested every day,” Chandran added. “The persons who are evaluated, depending on human behavior, are tested when they have symptoms.

"The wastewater testing gives us a general picture of the people in the community, not individual results."